Of the 137 species of grass considered native to Tasmania, only eight use the C4 photosynthetic pathway. There are also approximately 137 grass species considered as introduced to Tasmania and 21% of these are C4. In total, there are 41 species from 20 genera of C4 grass recorded from Tasmania. Many of the introduced C4 species have a very limited distribution, however, and are generally confined to urban areas and along roadsides. Overall, Tasmania has fewer C4 grasses than would be expected from climate alone and few of the C4 grass species are widely distributed or abundant. However, the proportion of grasses recorded from Tasmania that use the C4 pathway has been increasing for the past century and is still increasing. General distribution and habitat notes are provided for all C4 grasses known to be native or naturalised in Tasmania.